Sunday, September 02, 2007

(HealthDay News) -- An experimental nasal anthrax vaccine proved highly effective in tests in mice and guinea pigs, a University of Michigan Medical School study shows.

After it was placed inside the animals' noses, the vaccine triggered a strong immune response. All immunized guinea pigs survived after they received injections of 1,000 times the lethal dose of anthrax spores. All unprotected guinea pigs died.

From 40 percent to 70 percent of immunized animals survived after large doses of anthrax spores were placed directly in their nasal tissue.

In these animal experiments, there have been no significant side effects, and the vaccine has produced effective immunity for at least six months, the study said.

The nasal vaccine features tiny soybean oil droplets that are small enough to carry an anthrax protein inside the nasal membrane. Immune system cells then react to the anthrax protein and prime the entire immune system to attack anthrax.

This nasal vaccine is easier and more effective than the current injectable vaccine, according to the researchers. The nasal vaccine is also easier to store and use in locations where there is no available refrigeration.

The next step is to test whether the vaccine produces immunity in primates. The researchers are also preparing plans for safety studies in humans.

The study was published in the August issue of Infection and Immunity.

More informationThe U.S. Centers for Disease Control and Prevention has more about anthrax.